Question

当我运行代码时，只有在所有巨龙都没有健康或者所有舰船都没有健康之后，才能赢得胜利condition = true。
但是当它运行时，即使条件设置为仅在win条件为true时才离开，但do while循环似乎在第一次迭代后退出。
我似乎无法弄清楚为什么它无法继续运行，甚至在声明变量时分配了winCondition = false。
任何帮助将不胜感激。

#include<iostream>
#include<ctime>
#include<cstdlib>
using namespace std;

struct ship  //Creates type ship
{
  float shipHealth;
  int numOfPeople;
  bool capturedDragon;
};

struct dragon  //Creates type dragon
{
  string riderName;
  string dragonName;
  float dragonHealth;
  bool isCaptured = false;
};

int main()
{
  srand(time(NULL));

  const int MAX_SHIPS = 7;
  const int MAX_RIDERS = 5;

  int dragonHit;
  int dragonDamage;
  int dragonRemoveMenNumber;
  int shipDamage;
  int shipHit;
  bool winCondition = false;

  ship hunterShips[MAX_SHIPS];  //creates array of ships
  dragon dragonRiders[MAX_RIDERS];  //creates array of dragon/riders.

  for (int i = 0; i <= 4; i++)
  {
      cout << "Rider Name: " << endl;
      cin >> dragonRiders[i].riderName;
      cout << "Dragon Name: " << endl;
      cin >> dragonRiders[i].dragonName;
      dragonRiders[i].dragonHealth = rand() % (20 - 15 + 1) + 15;

  }

  for (int i = 0; i <= 6; i++)
  {
      hunterShips[i].shipHealth = rand() % (40 - 30 + 1) + 30;
      hunterShips[i].numOfPeople = rand() % (15 - 10 + 1) + 10;
  }


  do
  {

    for (int i = 0; i <= 4; i++)  //Dragons turn
    {
      if(dragonRiders[i].dragonHealth > 0 && dragonRiders[i].isCaptured == false)  //Dragon is alive
      {
        dragonHit = rand() % 10 + 1;
        if (dragonHit <= 7)  //Dragon hits target
        {
          if(hunterShips[i].shipHealth > 0 || hunterShips[i].numOfPeople > 0)
          {
            dragonDamage = rand() % (10 - 5 + 1) + 5; //Amount of Damage done
            cout << dragonRiders[i].dragonName << " hit and dealt " << dragonDamage << " damage. " << endl;

            if (dragonHit <= 3)  //Dragon takes men out
            { 
              dragonRemoveMenNumber = rand() % (3 - 2 + 1) + 2;
              cout << dragonRiders[i].dragonName << "Took out " << dragonRemoveMenNumber << " men" << endl;
              hunterShips[MAX_SHIPS].numOfPeople = hunterShips[MAX_SHIPS].numOfPeople - dragonRemoveMenNumber;  //Ships lose people
            } 

            hunterShips[MAX_SHIPS].shipHealth = hunterShips[MAX_SHIPS].shipHealth - dragonDamage;
          }
          else
          {
            cout << "All ships are destroyed, dragons win!" << endl;
            winCondition = true;
          }

        }

        else //Dragon misses target
          cout << dragonRiders[i].dragonName << " missed" << endl;
      }

      else  //Dragon is dead
        cout << dragonRiders[i].dragonName << " is dead or captured" << endl;  
    }





    for (int i = 0; i <= 6; i++) //Ships turn
    {
      if(hunterShips[i].shipHealth > 0 || hunterShips[i].numOfPeople > 0)  //ship is afloat
      {
        shipHit = rand() % 10 + 1;

        if (shipHit >= 7)  //40% chance to hit 
        {
          if(dragonRiders[i].dragonHealth > 0 && dragonRiders[i].isCaptured == false)
          {
            shipDamage = rand() % (5 - 4 + 1) + 4; //Damage done
            cout << "Ship dealt " << shipDamage << " damage" << endl;
            dragonRiders[MAX_RIDERS].dragonHealth = dragonRiders[MAX_RIDERS].dragonHealth - shipDamage;
          }
          else
          {
            cout << "All dragons are dead, ships win!" << endl;
            winCondition = true;
          }

        }
        else
          cout << "Ship missed. " << endl;
      }

      else
        cout << "Ship is sunk or out of men" << endl; //ship is sunk
    }

  } while (winCondition == true);
  return 0;
}

Answer 1

您的代码是

bool winCondition = false;
/* ... */
do {/* ... */}
while (winCondition == true);

，您想知道“即使winCondition = false，循环仍会退出”。您还将解释“条件设置为仅在获胜条件为真时才离开”。

我得出结论，您误解了do-while循环的语义是“直到满足条件才循环”。相反，它是“在满足条件时循环”。这意味着当winCondition评估为false时退出是预期的行为。

Answer 2

您正在初始化winCondition = false。 do..while循环将运行一次迭代，并评估不满足迭代条件winCondition == true，因此退出。

此外，如果do..while循环继续进行，则其中没有将winCondition设置为false的语句，因此循环将永远不会退出。

您是要用winCondition == false关闭do..while循环吗？

为什么即使条件评估为false，“ while循环”仍然不断退出？

2 个答案: